Transmission and fluid pressure clutch mechanism therefor



April 30, 1946. w. T. UVERMORE TRANSMISSION AND FLUID PRESSURE CLUTCHMECHANISM THEBEFOR original Filed Deo. 24. 1937 5 sheets-sheet 1 April30, 1946. w. T. LIVERMORE I TRANSMISSION AND FLUID PRESSURE CLUTCHMECHANISM THEREFOR original Filed nec. 24,` 1957 5 Sheets-Shea?l 2ATTORNEY.

INVENTOR am T/Mefmare April 30, 1946.

W. T. LIVERMO RE TRANSMISSION AND FLUID PRESSURE CLUTCH MECHANISMTHEREFOR Original Filed Deo. 24, 1937 5 Sheets-Sheet 3 t INVENTOR.ld/f//mm TL/k/e/mofe ATTORNEY.

Pl'lv30, 1946 w. T. LuvERMoRl-z 2,399,554

l TRANSMISSION AND FLUID PRESSURE CLUTCH MECHANISM THEREFOR OriginallFiled Dec. 24, 1957 5 Sheets-Sheet' 4 PI 30, 1945 w. T. Llvl-:RMORE2,399,554

TRANSMISSION AND FLUID PRESSURE CLUTCH MECHANISM THEREFOR Original FiledDec. 24, 1937 5 Sheets-Sheet 5 l INVENTOR. )W7/fam 7. We/"more VIIPatented Apr. 30, 1946 TRANSMISSION lANI) FLUID PRESSURE CLUTCHMECHANISM THEBEEOR William T. Livermore, Grosse Pointe, Mich.

Original application lDecember 24, 1937, Serial No. 181,679 Divided andthis application May 23, 1940, Serial No. 336,704

23 Claims;V

This invention relates to transmissions for use with automotive vehiclesand is particularly concerned with iiuid pressure actuated clutches andcontrol means therefor adapted for use in a type of transmission whichis automatically operated by a fluid pressure mechanism, therebyeliminatlng the necessity for manual gear shifting.

This application is a division of my co-pending application, Serial No.131,679, led December 24, 1937. Certain iundamentalfeatures of automatictransmissions have been developed by myself and are disclosed in United'States issued Patents 2,019,146, 2,100,810, 2,103,540 and 2,120,- 104.The present embodiment, although it includes certain features disclosedin my other ap# plications, is a development which has been the directresult of a considerable amount of additional research and experimentalwork. The present transmission clutch and control units are designedwith consideration for size and arrangement, thereby to provide acompact unit comparable in size with standard manually operated units. l

Several of my earlier designs of transmissions of*` the type describedin the aforementioned patent applications, comprise a plurality ofconstantly meshed gear trains one for each of the gear ratios desired,`there being an individual clutch to connect each individual gear trainfor operation. For automatic operation of this type of transmission afluid pressure mechanism was used to actuate the clutches, thismechanism being under the control of a unit which was actuated by thecombined effect of members movable in proportion to vehicle speed andengine output.

Thepresent invention, while employing many of the fundamental featureswhich were described and claimed in my previous applications, providesnovel and important improvements thereon in both the clutch arrangementand in the fluid pressure mechanism for automatically operating thetransmission. The gear and clutch unit in my improved design isconsiderably simplied both in number vof parts and manner of operation,there being two separate clutches of such size and arrangement that theymay be housed in the iiywheel in substantially the same space as thepresent Aday conventional clutch unit. These two clutches are suiilcientto provide automatic operation for three forward speeds by the provisionof an automatically operated shifting device which changes the gearratio of the gear train connected to one of the clutches while the otheris in operation. This. automatic gear shifting mechanism preferablyincludes a so-called synchronizer unit tomatic mechanism for operatingthe two clutches in the iiywheel. All of the above transmissionmechanism is particularly adapted for automatic operation by uidpressure mechanism to which novel additions have been vmade over mypreviously designed units,`

It is a primary object to provide a :Huid pressure operated clutchactuating unit which will be eective to prevent too sudden release ofthe clutch by provision of means to control the flow of fluid onreleaseof pressure from said clutch control unit. Such a type of control (l)prevents jerky shifting due to sudden release of the driving torque; (2)holds the engine speed down during the time when the change in gearratio is made; (3) prevents full release of the driving torque duringthe period when change in gear ratio is being effected. Y

It is a further object to provide for clutch operation by fluid pressureactuated mechanism reacting and contained in a member rotating with theclutch, the rotating member being supported for rotation in a stationaryhousing, which housing also has means provided therein for feeding fluidunder pressure for operating the clutch.

It is another object to provide uid pressure operated mechanism havingthe advantageous feature of rotation with the clutch with means forpreventing iiuid used to actuate said fluid pressure l mechanism fromreaching the contacting parts of said clutch.

It is a further object to provide a mounting for a uid pressure operatedclutch operating member exibly supported in the housingy relative to theclutch and relative to the other parts of the transmission, thereby toallow for misalignment of parts.

It is another object to provide fluid Pressure mechanism for operatingthe clutches, rotating with said clutches and exlbly supported relativeto the transmission and clutch mechanism, said rotating mechanism alsobeing used to carry a journal for a sleeve which connects one of theclutches with certain of the transmission gearing.

It is another object to provide means for'lpreventing the iiuid pressureoperating mechanism from changing the clutch connection before thesynchronizer unit which has started its movement has effected positiveconnection between the rotating parts.

It is another object to provide a gear changing mechanism of the typeemploying a synchronizing means for bringing rotating parts to the samerotative speed before effecting positive connection thereof, withautomatic means for operating said mechanism including means to effect apause in the movement of the actuating mechanism during the time theparts are being brought to the same rotative speed, followed by a rapidmotion of the actuating mechanism to complete the positive connection Itis a further object to provide a fluid pressure mechanism for operatinga gear changing mechanism of the synchronizing type which will produce adesired variation in the rate of movement of its operating parts bycontrol of the flow of fluid under pressure.

It is another object to provide for the control of a gear changingmechanism of the synchronizing type using fluid pressure for itsoperation so arranged that the full pressure available in the uidpressure system will be effective to actuate the mechanism, means beingprovided to drain off fluid which leaks past the actuating parts,thereby to prevent building up of pressures in other parts of the systemwhich would oppose movement of said actuating parts.

The above and other objects of the invention will appear more fully fromthe following detailed description of a practical embodiment of theinvention and by reference to the accompanying drawings forming a parthereof and wherein:

Fig. 1 is a vertical section through a completely assembled transmissionunit showing the general arrangement of the several parts.

Fig. 2 is a diagrammatic view showing particularly the arrangement ofthe fluid pressure mechanism for automatic operation of the transmissionunit.

Fig. 2a is a view taken substantially on the line 2a-2a of Fig. 1showing particularly the position of the fluid pressure controlmechanism housing at the side of the transmission unit.

Fig. 2b shows mechanism for producing slower operation of thetransmission when the toe button control is actuated to shift thetransmission to a lower speed.

Fig. 2c shows mechanism used to assure rapid build-up of pressure duringthe first part of the time used to actuate the clutches followed by aslow build-up of pressure near the end of the time required to actuatethe clutches.

Fig. 3 is a section taken substantially on the line 3--3 of Fig. 2a andshows a. section through the uid pressure control unit and discloses inpartial detail the accumulator piston, the pressure control valve, theselector valve and the differential lever.

Fig. 4 is a horizontal section taken substantially on the line 4 4 ofFig. 2a and shows particularly the mechanism for automatic operation ofthe synchronizer unit.

Fig. 4a is a view of the synchronizer operating piston and cylinder andshows particularly the fluid pressure conduit system for operating thisunit.

Fig. 5 is a vertical section taken substantially on the line 5-5 of Fig.3 and shows a crosssectional view of several of the fluid pressurecontrol units.

Fig. 6 is a fragmentary sectional view taken substantially on the linel-l of Fig. 3 and shows an end view of the lever mechanism shown in theside view of Fig. 3.

Fig. 7 is a top fragmentary sectional view taken substantially on theline 'I-1 of Fig. 1 and shows a part of the connecting linkage betweenthe Vehicle speed responsive governor and the differential lever.

Fig. 8 is a. fragmentary section taken substantially on the line 8-8 ofFig. '1 and shows further details of a part of the linkage connectingthe governor and the differential lever as well as the shifter forks foroperating the synchronizer unit and reverse drive.

Fig. 9 is a view intended primarily to show the means for rendering theautomatic gear shifting mechanism inoperative when the transmission isset in reverse drive position, the view showing the parts as they wouldbe seen from the top of Fig. 8 with a portion of the housing removed andalso partly broken away.

Fig. 10 is a section taken substantially on the line III- I0 of Fig. 7and shows details of the lever mechanism connected with the governorcontrol.

Fig. 11 is a section through a clutch plate and facing showing aresilient mounting between a clutch plate and its facing.

Fig. 12 is a view taken substantially on the line I2--I2 of Fig. 11 andshows further details of the resilient member between a clutch facingand a clutch plate.

GENERAL ARRANGEMENT Referring to Fig. 1, there is shown a sectionthrough a transmission disclosing the general arrangement of the gearand clutch unit together with a portion of the fluid pressure mechanismand controls.

The general scheme of the arrangement shown in'Fig. 1 requires twoclutches I0, Il, which are enclosed within a fly-wheel I2, the combinedde- Sign of ily-wheel and clutches being so worked out that the size ofthe fly-wheel unit is not increased unduly by the addition of the twoclutches. By a fluid pressure mechanism designated generally as I3 whichis designed to rotate with the fly-wheel the clutches I0 and Il areactuated to either connect the engine driven fly-wheel I2 to a mainshaft Il or to a sleeve I5. The sleeve I5 has a gear I6 attached at itsouter end. The main driving shaft Il extends entirely through thetransmission and, therefore, when the engine driven fly-wheel isdirectly connected with shaft I 4 by means of the clutch II a directdrive is effected. Normally free to rotate upon shaft I4 are providedtwo gear units, I1 and I8, which may be selectively connected to rotatepositively with shaft I4 by means of synchronizer unit I9. Acounter-shaft 2| is provided below the main shaft I4 and has mountedthereon a gear 22, which is constantly meshed with gear I6 of the sleeveI5. Also mounted on counter-shaft 2l and formed integral with gear 22 isa gear 23 which is in constant mesh with gear I1, which may be connectedwith drive shaft Il by synchronizer I9. Gear unit Il is of spool shapeand has two gears at the ends thereof, namely 24 and 25. Connected tocounter-shaft 2I by suitable splined connections so as to rotatetherewith, but free to slide lengthwise thereof, are a pair of gears 26,2'I, adapted to be actuated for sliding movement by fork 28, a portionof which is shown in Fig. 1. When the gear unit 26, 21 is moved assautto the right along shaft 2|, as shown in Fig. l, the gear 23 will meshwith the gear 2ly and on still further movement toward the richt, thegear 2l will mesh with the gear 25.

As 'the gear and clutch set-up is shown in Fig. 1, and using the partsabove described, the device operates substantially as follows: For lowgear, the gear unit 2B, 21 is moved to maximum distance to the right sothat gear 25 is in mesh with gear 21. The clutch II! is actuated by thefluid pressure mechanism, later to be described, and the engine drivenily-Wheel I2 is thereby connected with the sleeve I5 causing rotation ofthe gear I6. The gear 22 is driven by gear I3 and rotates shaft 2|,carrying gear 21 which meshes with gear 25 on shaft Il. Since at thistime the synchroniser I3 has been moved to connect gear unit I3 and gear25 to the shaft Il, the drive is completed.

For second speed, the gear 23 is iirst put in mesh with gear 24 and thesame gearing above described effects second speed. For trame driving themanually moved gears 26, 21 are left in position so that the gear 28 ismeshed with the gear 24. The automatic control of the device is used tochange the gearing from the normal second speed to direct drive and thento over-drive. This is accomplished by a uid pressure unit which movesthe synchronizer I3 in timed relation with the duid pressure unit whichengages and disengages clutches I0 and i! at the proper time.

The shift from second speed, to thenext higher ratio of direct drive iseffected by the iiuid pressure mechanism first actuating the clutch Ilto connect the fly-wheel I2 directly with the shaft I4 and releasingclutch III, thereby removing the driving load from the low gear trainand synchrcnizer and applying it directly to the shaft Il. The next stepis to actuate the synchronizer i3 by moving the collar thereof towardthe left as shown in Fig. 1. This movement disconnects the gear unit I3from the shaft I4 and eiects connection of gear I1 to said shaft Il.

The change from direct drive to over drive is eiected by disconnectingclutch and connecting clutch I0, the synchronizer |3 having beenpreviously actuated to connect the gear I1 to the shaft I l. The drivethen is through sleeve I5, gear I6, gear 22, gear 23, gear |1 and outthrough shaft i4.

The arrangement of clutches and gearing makes it possible to haveclutches which are engaged alternately to establish driving connectionthrough various drive ratios and means for automatically altering theratio through one of them while the drive is through the other.

It is understood that the automatic mechanism for effecting thesechanges is controlled by other automatic units later to be described butthe present description is for the purpose of showing the general schemeof gear, clutch and synchronizer set-up. i'

The movement of the gears 23 and 21 along shaft 2| is intended to bemanual and there is also provided a reverse counter-shaft 23, with asuitable gear 29a (Fig. 8), with which gear 26 may be meshed by movementtoward the left from the position shown in Fig. 1. Therefore, with themanual movement of the gear unit 2l, 21 along counter-shaft 2| it ispossible to eil'ect reverse drive or to set :up the unit for starting ineither low or trafl'lc second speed. For ordinary city traffic driving.the unit would be left in the second speed position and automaticoperation would be` edected from second through direct driveand theninto over drive, thus anording three automatic speeds. lt is. of course,apparent that the gear unit could be designed to provide three automaticspeeds of any desired ratio with possibility of changing one of thesespeeds to a different ratio by manual operation. and, in addition, toprovide a manually controlled reverse.

It is particularly to be noted that this transmission set-up makes itpossible to disconnect the lower drive ratio gears from the propellershaft when the higher ratio gears are in operation, thereby eliminatingthe idle running of the low speed clutch and gearing at excessive speedsduring high speed operation. This feature is noted with reference toFig. 1 where it is apparent that when the unit is in over-driveposition, where it remains for a major portion o! the time, the gearunit I3 will be disconnected from shaft Il. Gear unit I8, shaft 2| andgears 22, 23, 26 and 21 are then driven at relatively low speeds vthrough gear I1.

As shown and described, the transmission provides three forward speedsadapted for automatic operation with a fourth ratio available with amanual shift. Obviously the three speeds for automatic operation mightbe selected at a different ratiothan herein shown without change inprinciple.

As previously mentioned, the mechanism for operating the clutches Illand il of the transmission is mounted for rotation with the ily-wheeland clutch unit. The mechanism is fluid pressure operated and comprisesa plurality of pistons and cylinders mounted in a member 30 which is ofsuch. shape as to be mounted upon and surround the sleeve member I 5, aprojecting circular portion of the member 30 providing space for sixhorizontally disposed cylindrical openings. three ofA these cylinderswith suitable pistons being f used for actuation of the clutch IIl andthe other three being used to actuate the clutch II. The member 30 issecured to rotate with the fly-wheel I2 and secured from endwisemovement by screw 30a, shown in Fig. 1. The six cylinder and pistonunits may be spaced around the member 3l! in any suitable position sothat three equally spaced lever units for each clutch may be actuated.There is shown in Fig. 1 one cylinder unit 3l for actuating the clutchI0 and also one of the three cylinders 32 for actuating the clutch It isunderstood that the other two units of each set are of similarconstruction. Considering the actuating unitfor clutch II), a piston 33is mounted in the cylinder 3| with suitable connections to a lever 34which is pivoted at 35 and actuates a rod 36 connected with the clutchIIl, as shown. It istherefore apparent on inspection of Fig. 1 that amovementof the piston 33 toward the left will move the connectinglinkage in such direction l as to engage the clutch IIJ and therebyconnect the engine driven ily-wheel I2 to rotate sleeve I5. Similarly,the other set of cylinders will actuate the clutch II through a piston31, a lever 36 pivoted at 33, and a connecting rod 40. It is noted thatthe lever 3,8 is so pivoted relative to the od 43 that movement of thepiston 31pushes the rod I0 toward the left, as shown in Fig. 1, whichdirection of movement actuates the clutch I and connects the ily-wheelI2 to rotate the shaft I4. It is an important feature of the abovedescribed construction that the endwise reaction .from the pistons istransmitted to the ily-wheel through the connection effected by the setscrew 30a and since the whole clutch operating unit 30 rotates with theily-wheel, the endwise reaction from this unit is not transmitted to thebearings oi' the transmission or engine.

TRANSMISSION OPERATING MEcHANrsM There is shown in Fig. 2 a diagrammaticview of the several units of the fluid pressure control mechanism whichmake up the unit for automatic operation of a transmission of thegeneral type just described. In the mechanism illustrated in Fig. 2there is provision for operation of two clutches, one of which operatesa first and a third speed, and the other of which operates a secondspeed, these clutch operating members being designated as pistons |2|and |22. The synchronizer shifter fork |23 is for the purpose ofchanging the connection from iirst to third speed While the second speedclutch piston |22 is in operation.

It is understood that the first, second and third speeds. as designatedabove, might be the second, direct and over-drive ratios, respectively,as disclosed in the transmission shown in Fig. l and previouslydescribed. Obviously, however, the same type` of operating mechanism asherein disclosed might well be used to operate a transmission having theconventiona1 low, intermediate and high speed ratios.

The mechanism for automatic operation is actuated by iiuid underpressure, A pump |24 is driven from the engine of the vehicle and drawsoil from a sump provided in the lower part of the transmission throughan intake conduit |25, fluid under pressure being delivered to a pumpoutlet conduit |26 which leads to accumulator chamber |21. A springloaded accumulator piston |28 is mounted for operation above theaccumulator chamber |21 and serves to limit the maximum pressureavailable in the accumulator chamber' by provision of a by-pass |29which leads to the sump and which is in a position to be lIopened whenthe spring loaded piston |28 passes a definite position. An outlet |3|from the accumulator chamber is provided and a check valve "|32 allowsone-way movement of the oil from the accumulator chamber |21 intoconduit |33.

For the purpose of providing a variation in the size of the conduitleading from the accumulator chamber, a jet changer |34 is provided.This unit comprises a sliding member |36 with various sizes of openingstherein, and in the particular unit used for illustration there is alarge opening |31 and a small restricted opening |38. The small oriiice|38 is placed in position for operation when it is desired tohave aslower clutch engaging movement of the device and the largerunrestricted openingl|31 is used when faster clutch engaging movement isdesired. The continuation of the conduit |33'ishere shown as a smallerpassage |33a which leads to the inlet opening |39 of a pressure controlvalve |4|. The smaller size of conduit |33a results in a slow iiuid iiowwhen the iiuid is cold as in starting with a cold engine. The functionof the pressure control valve 4| is to provide required variation in thepressure of the oil used to actuate the clutch operating pistons |2| and|22. It is to be understood that for most eflicient clutch engagementthere is of necessity a lower operating pressure required at smallthrottle openings than is required at greater throttle openings. Thepressure control valve is connected to the throttle control by a stem|42 which abuts at its lower end with a plug |42a engaging the upper endof a spring |43 mounted in the bottom of the pressure control valvecylinder. With the opening of the throttle the stem |42 is presseddownwardly therebyI reducing the tendency of spring |43 to compressspring |43a, thus relieving the pressure on valve lt and permitting theiiuid pressure in conduit E48 to increase. The upper end o! the pressurecontrol valve has a valve member |41 held by a spring |48 to close theend of a sump outlet opening |49. Springs |48 and |43a are of suchstrength that valve |41 will always hold any pressure admitted throughvalve |44 but provides an outlet to reduce the pressure in conduct |46when the throttle is released. With increase in throttle opening thedownward movement of the valve stem |42 reduces the compression of inletvalve spring |43a and increases the compression of outlet valve spring|48, thereby allowing maximum pressure available to be fed into conduit|46 and held there. However, when the throttle is near its closedposition outlet valve spring |48 will be less compressed and will allowvalve |41 to release, thereby providing a lower fluid pressure inconduit |46 at small throttle openings.

As shown, there are three separate outlet conduits branching from theconduit |48, i. e., |5|, |52 and |53. These conduits are positioned toopen into a selector valve cylinder |54 in which a selector valve member|56 is mounted for sliding movement.

Although the design of selector valve shown herein provides some newfeatures, the general arrangements of the valve and its housing aresimilar to that employed in my co-pending applications, Serial Nos.584,812 and 715,065 and in my United States Patent No. 2,019,146. In theconstructions described in the above applications. fluid under pressureis fed to desired units by positioning the valve to connect ports whichopen into the valve cylinder, suitable annular rings being cut in thevalve body to connect the inlet ports with outlet ports on the oppositeside of the valve cylinder when the valve body is in proper alignment.

The mechanism for positioning the selector valve will be describedlater. For the present it is suilicient to state that means is providedto move the valve body |56 progressively upward, as shown in Fig. 2,when it is desired to shift through the available range from lower tohigher gear ratios and in opposite direction to shift from higher tolower gear ratios. This positioning mechanism, as will later appear, ispreferably automatic in operation, but it is to be understood that manyadvantages of the fluid Dressure operating mechanism would remainregardless of the means used to position the selector valve.

Continuing with the description of the showing in Fig. 2, the outletconduits |5|, |52 and |53 are spaced along, and open into, the selectorvalve cylinder |54. The body of the selector valve member |56 has anannular groove |51 cut in its periphery and the valve member |56 isshown po sitioned to connect through this groove |51, the

loutlet conduit |52 with the conduit |58 on the opposite side of theselector valve opening. The conduit |58 leads directly to cylinder |59for operating the clutch operating piston |2|. As here shown, the pistonis being actuated to operate the clutch to effect'flrst or low speed ofthe vehicle. Also in the selector valve member |56, a drilled opening|6| is provided which opens into the hollow central portion of theselector valve 'be explained presently.

member |58 and connects to the sump. The drilled opening I 6| is sopositioned when groove |51 connects conduits |52 and |58 as to alignwith a conduit |52 which is connected to a cylinder |59a for operationof another clutch operating piston |22. Thealignment of opening |6| withconduit |62 connects cylinder |59a with the sump and releases allpressure therein and it follows that the clutch which is operated by thepiston |22 must then of necessity be disengaged.

It is noted that the conduit |52 is provided with a restricted openingfor the purpose of eiIecting a slow engagement of the ilrst or low speedclutchV to simulate the conditions found most advantageous for thisoperation.

Also provided in the selector valve member |56 is a drilled opening |54which is more restricted than the similar opening |I. Like the opening|6I, the opening |84 connects the outside or the selector valve member|56 with its hollow central portion and is so positioned that when theselector valve member |55 moves upwardly the drilled opening |54 is inalignment with the conduit |58 leading to the cylinder |59 of the iirstspeed clutchpiston |2|. This connection results in the release ofpressure in said cylinder |59 through the restricted opening |64 therebyeffecting a slow release of the iirst speed clutch. The same upwardmovement of the selector valve member |56 causes the annular groove |51to come in alignment with the conduits |52 and |58, thereby effecting aconnection betweenthese two conduits and allowing fluid under pressurefrom conduit |46 to be admitted to conduit |52 and thence into cylinder|5911 to actuate piston |22 which engages the second speed clutch. Bythe movement of the selector valve member |56 just described there hasbeen eiected a reversal of the clutches, i. e., clutch operating piston2| has thrown its clutch out of engagement and clutch operating piston|22 has had the pressure admitted to its cylinder to engage the clutchattached thereto. I

As the car increases in speed the control mechanism continues to movethe selector valve in an upward direction. Adjacent the last mentioneddrilled opening |64 in the selector valve |56 there is provided anannular groove |66 which is similar to the groove |51 but of greaterlength. The groove |65 is of such length and position that when itsupper edge comes into alignment with the conduit |55 it bridges theconduits |5| and |52 so that there is an unrestricted iiow of fluidunder pressure into the conduit |58 to again actuate the piston |2|,this time for a third or highest speed operation, the ratio of the vgearing having been changed by the operation of the-shifter fork |23 ina manner which will The reason for the bridging of the conduits |5| and|52 by the longer annular opening |55 is because it is not desired tohave the inlet of fluid under pressure to actuate this clutch for thirdspeed to be a restricted or slow movement as was the case when the sameclutch was previously actuated from the conduit |52 alone for firstspeed. The same movement of the selector valve member |55 which bridgesthe conduits |5| and |52 by annular opening |55 and connects them withconduit |58, places the restricted outlet conduit |64 in position torelease pressure from conduit |62, thereby effecting a gradual releaseof piston |22 and the clutch connected therewith. The positioning of thevarious annular grooves of the selector valve and the provisiono!restricted and unrestricted openings positioned as above describedresults in a proper timing of the operation of the clutches by providingthe required amount of overlap between the actuation and release ofconsecutively operated clutches, thereby preventing both racing of theengine and objectionable jerking of the car.

'I'here has been described above the mechanism which iirst actuates therst speed clutch, then throws it out of engagement and actuates thesecond speed clutch, then releases the second speed clutch and actuatesthe rst mentioned clutch a second time, this time for third speedoperation. The mechanism for operating the synchronizer which makes itpossible to change the gearing connected with the rst and third speedclutch so that this clutch may be used for the dual purpose mentionedwill now be considered.

synchroniser operating mechanism The fluid under pressure for theactuation of the synchronizer operating mechanism does not come throughthe pressure control valve as does that used for actuating the clutches,it being unnecessary when shiiting this unit to change the pressure forvarying degrees of throttle opening. For effecting this result a conduit|1| leads directly from the accumulator chamber |21 and connects withthe conduit |12 which leads to two selector valve inlet ports |13 and|14. Fluid under pressure from the accumulator chamber is thus madeavailable at the selector valve. In the position shown in Fig. 2,pressure from the conduit |14 is being allowed to enter a conduit |16because of the alignment of an annular groove |11 in valve member |56with the conduits |13 and |16. At the same time a drilled opening |15leading into the center of the selector valve member |56 is placed incommunication with a conduit |19, thereby connecting said conduit |19with the sump and releasing all pressure therein. As shown in Fig. 2,conduit |16 leads to one end of a cylindrical chamber |8I, the

- in a direction toward said chamber.

conduit having means to provide a restriction to flow in the directionaway from the cylindrical chamber |8| but to allow free passage of iluidThis result is accomplished by a star-shaped oriiice member mounted inthe conduit as indicated at |82 so that movement of uid in the directiontoward the chamber |8| allows the orice member to lift oi its seat andallow free passage of the iluid under pressure, while in the oppositedirection the orifice member is seated and provides a restriction in theconduit |16.

The conduit |19 previously mentioned leads to the opposite end of thecylindrical chamber |8| and is similar in shape and coniguration toconduit |16, there being an orice |83 similar to |82 which providesrestriction to flow away from cylindrical chamber |8| and unrestrictednow toward said chamber. A synchronizer operating piston |84 is mountedfor reciprocation in cylindrical chamber |8| and by its reciprocationmoves the synchroniser operating shaft |85 on the end of which ismounted the previously mentioned synchronizer shifter fork |23. From thegeneral lay-out just described, andby reference to Fig. 2, it isapparent that the piston |84 is moved in one direction by admission ofuid under pressure through conduit |19 and in the opposite direction byadmission of uid under pressure through conduit |16. When one of theseconduits is connected to the pressure line, the

other must of necessity be connected to the sump so that oil in the lowpressure end of the cylinder will be allowed to ilow out. For thepurpose of controlling the movement of the piston |88 the previouslymentioned orifices |82 and |83 act in such manner that there is arestriction to flow of fluid out from the cylinder |8| while the fluidunder pressure entering the opposite end of the cylinder is alwaysallowed to enter unrestricted. This feature is considered importantsince it allows control of the rate of movement while still maintainingfull pressure on oneI end of the piston. In this connection an importantand novel feature has been incorporated in the design of thesynchronizer operating piston by provision of an annular groove |88aaround the central portion of the piston, this annular groove beingdrained to the sump through an opening |88b in the casing of cylinder|8|- It has been found that such a construction is very advantageous.Since the control of flow is effected by a restricted orifice on theoutlet side of the piston, if fluid under pressure from the inlet sideshould leak past the piston it would have a direct eiIect on the rate ofmovement of the piston, andwould produce a back pressure against theoutlet side of the piston. However, if leakage from the inlet side isdrained oi at the center, the restricted outlet is free to control themovement without any detrimental build-up of pressure by leakage pastthe piston, In this way full pressure from the inlet to move the pistonis assured, whereas if the leakage were allowed to build up on theoutlet side, the full inlet pressure would not be available because itwould be partly oifset by leakage pressure on the opposite side of thepiston.

Considering the operation of the synchronizer shifting unit inconnection with the mechanism for operating the clutch pistons |2| and|22, previously described, it is apparent because of the positions ofgroove |11 and drilled opening |18 relative to conduits |18 and |18 thatthe synchronizer operating piston will be subjected to pressure such asto hold it in the position shown in Fig. 2 until the selector valve hasmoved upwardly by increase of car speed a distance sufficient to bringdrilled opening |18 in alignment with conduit |18. When this position isreached the pressure line previously connected with conduit |18 will becut oiI and drilled opening |18 will connect conduit |18 with the sumpand release pressure therein while a second annular groove |88 willconnect the pressure line with conduit |19. Because of the admission ofuid under pressure through said conduit to the lower end of cylindricalopening |8|, the piston |84 will be moved in an upward directioncarrying with it the synchronizer operating shaft |85.

The ports and grooves of the selector valve for operating the clutchesand the synchronizer are so positioned relative to each other that onupward movement of the valve member |58 the previously described releaseof pressure on piston |2| and the admission of pressure to piston |22are both effected before the pressure is reversed on the synchronizercylinder to start its movement in the opposite direction. When thesechanges in pressure ilow have been accomplished and the synchronizerpiston started on its travel it is necessary that pressure conditionsremain unchanged until the shift of the synchronizer is completed,because power applied by the clutch engaged by piston |2| is transmittedthrough the synchronizer, and should this clutch be engaged while thesynchronizer is in motion, damage would result. Satisfactory operationis assured by the provision of interlock pins |81 and |88 which serve tohold the selector valve member |58 from further movement untilthesynchronizer piston has reached its maximum movement and completed itswork. Two recesses |88 and |88 in the synchronizer operating shaft arepositioned to allow the pins |81 and |88 to move backwardly away fromannular projections ISI and |82 when the synchronizer shaft |85 reachesthe end of its travel. 'I'he two interlock pins |81 and |88 are spacedas shown in Fig. 2 for the reason that one of them acts when thesynchronizer movement is in one direction and the other when themovement is in the opposite direction, the relative positioning of thepins and the projections being such as to effect the required fixedpositioning of the selector valve during the time necessary to completethe synchronizer shift. When the synchronizer operating shaft comes tothe end of its travel in either direction, pin |81 or |88 drops into theslot and away from the projection against which it has been riding, andthe selector valve is again free to move and on further upward movementwill change the alignment of the drilled openings |5| or |88 and theannular groove |51 to reverse the pressure conditions in the conduits|58 and |82, thereby to put the opposite clutch |2| in operation foreffecting the third forward speed.

A control cable unit |88 is used to connect the sliding member |88 ofthe previously mentioned jet changer |38 with the end of thesynchronizer operating shaft. By this connection the large lessrestricted opening |81 is placed in position for communication with theconduit |38 when the synchronizer is in position for low speed, as shownin Fig. 2, while in the opposite position of the synchronizer the actionof the control cable is to move the sliding member |88 of the jetchanger to place the more restricted opening |88 in position foroperation in the conduit |38, the effect of which will be to provide aslower shifting action for shifting down from third to second speed thenup from first to second. The purpose of this arrangement is to providean interval of time during the shift from third to second to permit theengine to accelerate to a proper speed to drive the car in second. Ifthe shift is completed too soon, the car will drive the enginemomentarily, producing an unpleasant drive reversal or backlas Thedesired result is accomplished by the jet changing device withoutdelaying the shift from first to second. which must be made promptly toprevent the engine from racing unduly during the shift. It is to benoted that when shifting from a high gear to a lower one, the enginemust increase its speed, whereas when shifting from a low to a highergear the engine speed must be decreased by the clutch application. Thejet changer connected as shown provides proper time intervals for the upshift from first to second and the down shift from third to second. Itseffect on the other shifts is relatively unimportant.

Further details of the synchronizer operating piston and its springconnected synchronizer operating shaft |85 will be considered when theactual unit is described in another section. It is also to be understoodthat the term synchronizer" as used in the above description might wellinclude several different types of mechanism for changing gear ratio bya transverse shift of a member such as shown at |28.

In the upper portion of Fig. 2 there are shown certain controlmechanisms. The general arrangement oi' the control for actuating theselector valve by the combined or dinerential action of vehiclespeed andthrottle control position, although including certain additional andnovel features, is similar to that described in my copendingapplication, Serial No. 603,823. There is shown in Fig. 2 a governor |94driven at vehicle speed which actuates one end of a dierential lever |95and a throttle and foot accelerator unit which through rod |95 actuatesthe opposite end of the dlierential lever |98. The lever |96 is pivotedon the selector valve control rod |91 and thereby the selector valve ispositioned by the differential effect of throttle control position andvehicle speed.

The carburetor and throttle unit of the engine is shown at |98 withconnection to the throttle for both hand operation and foot accelerator.The connection between the accelerator pedal and the throttle is eectedby a rod 50 in which is incorporated a thermostatic element E The bellcrank lever 52 connects the rod 60 with the vertical rod |95 whichconnects with the diierential lever |95. The use of the thermostaticelement 8| in the connection between the throttle and the diiierentiallever, as above outlined, provides an automatic adjustment for variationwith tem- Derature which is very important for use with hydraulicoperated transmissions depending on the throttle for control. In thepresent case the throttle being connected to actuate one end of thediiferential lever |95 and secondarily connected to actuate the pressurecontrol valve through rod |42, the thermostatic element 6| will vary therelative position between the throttle and the units it controls.

With the use of the throttle as one of the elements for controlling theautomatic transmission it follows that the operation of the acceleratorpedal 62 will automatically operate the iluid pressure control systemfor the transmission, and 'it can be imagined that this would not bealways desired. In order to provide an independent control of the enginethrottle which will not also operate the transmission control mechanism,a sep` arate hand throttle unit 80 is provided, as shown in the upperportion of Fig, 2. This hand throttle control is connected to a separatethrottle lever 8| by control cable 92. The lever 8| actuates thethrottle without moving the rod 60 or the accelerator pedal and itsconnection |95 to the pressure inthe system and disengage any clutchwhich may be in engagement. In other words, the same result as inconventionally-controlled cars is accomplished by the downward pressureof the clutch pedal, i. e., the throwing out of the clutch.

The connection of the clutch pedal to the accumulator piston servesanother purpose, namely, that ot an auxiliary pump for emergencyoperation when required. This result is accomplished by working theclutch pedal up and down and thereby reciprocating the accumulatorpiston |28. Because of the provision of a check valve 20| oil is drawninto the accumulator chamber |21 from the sump and the pressureincreased in the chamber to a sufficient amount for emergency operationof the device.

Near the accelerator pedal in Fig. 2 there is shown a second and rstgear toe-button 202 which is used to hold the upper end of the selectorvalve control rod in position so that it will not shift out of second orrst gear as may be desired dependingupon the amount of movement given tothe toe-button 202.

As shown in Fig. 2b, it is intended to incorporate with the toe-buttoncontrol 202 a means to change the rate of clutch application for thepurpose or eiecting a slower build-up of pressure when the shifting bymeans of the toe-button is from a higher speed to a lower` speed, suchas is the condition when shifting down to the second speed position touse the second gear for the purpose of retarding the motion of the car.vAs shown in Fig. 2b, this is accomplished by two sizes of jetsinterposed in the uid pressure system and controlled by the rod 63 whichis actuated by the movement of the toe-button 202. The conduit 61 leadsfrom the accumulator cylinder and branches into conduits 65 and 6B whichare connected with the vertical opening 68, the

` outlet to the pressure control valve being shown at 69. The rod 53controls a piston member 64 which covers an unrestricted opening inconduit $5 and forces the liquid to go through a restricted jet 58.Therefore, whenever the toe-button 202 is depressed to hold thetransmission in the second speed position the piston 64 will cover theunrestricted opening and force the iluid pressure to flow through therestricted jet 66 and therefore produce a slower operation of thetransmission.v y

Although in Fig. 2b the rod 63 which controls the closing of theunrestricted opening B5 is shown operated by the toe-button 202, such aunit might also be set up to be actuated by the vehicle speed governorand when so connected would provide means to assure `slower operation ofthe fluid pressure actuating mechanism at higher vehicle speeds therebyincreasing the time required for clutch application at the higherspeeds. Them unit shown in Fig. 2b actuated by the governor would be ina position to furnish unrestricted flow of uid under pressure at lowspeeds,` but as the speed of the governor increased would close theopening 55 and thereby require slower operation by forcing the fluidunderl pressure to go through the restricted opening 68. Similarly, itmight be possible to actuate the unit by means of a thermostatic elementand thereby vary the time required to actuate the clutches in proportionto temperature conditions. It has been found in operation of fluidpressure transmissions of this type that it is important to providemeans between the pressure control valve and the selector valve to allowthe pressure to build up very quickly at the beginning of any clutchapplication, but as the maximum pressure actuating the clutch isapproached it is very advantageous that the pressure then build up moreslowly. This is accomplished by the mechanism shown in Fig. 2c whereinconduit marked 10 leads from the pressure control valve and branchesinto conduit 1| having a large opening provided with a 'ball check valve12 retained by a spring 13.

The other branch of the conduit 1|a contains a restricted oriilce 14.The two branched conduits both connect into the conduit which leads tothe selector valve. In the branched conduit 1| in which is incorporatedthe large oriilce and the spring retained ball check valve, the spring13 is so selected as to hold the check valve closed to a pressure alittle under the maximum pressure which is desired. Therefore, at thebeginning of any pressure change the high pressure which is naturallythrown into the conduit 1| will hold the ball check valve 12 open andallow flow through the unrestricted opening and the pressure willtherefore build up quickly. However. as the pressure builds up in theconduit 15 and the maximum pressure is approached the spring 13 willcause the bell check valve to be closed and force the flow to go throughthe restricted jet 14 and therefore during the remaining time of thebuildup to the desired maximum the change will be a slower one.

DETAILS OF MECHANISM FOR AUTOMATIC OPERATION The basic features of thefluid pressure mechanism for automatic operation have been described inconnection with the diagrammatic disclosure in Fig. 2. However, for thepurpose of demonstrating the actual application of my ideas to apractical structure and also to disclose certain additional novelfeatures of the device, there is shown in the drawings and describedhereinafter, a mechanism suitable for actual operation and assembly withthe transmission unit shown in Fig. 1.

The mechanism will be described under the following headings:

(a) Fluid pressure pump;

(b) Accumulator;

(c) Pressure control valve;

(d) Selector valve and connections to actuating units:

(e) Synchronizer control cylinder and control parts to connect withsynchronizer;

(f) Synchronizer and selector valve interlock;

(g) Governor;

(h) Controls from governor and throttle to dii'- ferential lever;

(i) Reverse interlock;

(j) Clutch operating mechanism and support in transmission housing;

(Ic) Details of clutch construction to adapt for automatic operation.

(a) Fluid pressure pump Referring to Figs. 1 and 5, it is noted that afluid pressure pump numbered 50 is mounted in the lower central portionof the transmission housing. This pump, as shown in Fig. l, has attachedto its shaft a gear 5I which is driven from (b) Accumulator Referring toFig. 3, a piston 20.9 is mounted in the accumulator cylinder 201 abovementioned.

2|3. When the pressure in cylinder 201 becomes suflicient to move piston209 past an opening 2|6 (see Fig. 3) the fluid is by-passed back througha conduit 2| 1 which is connected with the sump. The result is that thepressure in the accumulator cylinder is maintained at a pressuredetermined by spring 2|| and when such pressure exceeds a denite amountthe fiuid is by-passed to limit the pressure accordingly.

As shown in Fig. 3, there is provided a shaft 2| 4 which is secured tothe piston 209 and projects outwardly of the housing as shown. Whensuitable actuating means are provided 01' this shaft it is possible touse the accumulator piston as an auxiliary pump. For such use the pistonis reciprocated and draws oil from the sump at 208 through check valve204 into conduits 206 and 208 and thence into the cylinder 201 (see Fig.5). K

At the top of the accumlator cylinder 201 (see Figs. 3 and 5) there isprovided an outlet conduit 2|8 (see Fig. 5) from the accumulator inwhich conduit is a ball check valve 2|9. This conduit 2 I 8 connectswith a pressure conduit 22| (see Figs. 3 and 5) which carries the fluidunder pressure from the accumulator cylinder to a conduit 222 having arestriction therein (see Fig. 5) which opens into the pressure controlvalve cylinder 223.

v(c) Pressure control valve The function of the pressure control valveis to provide for changes in the pressure of clutch application betweenlarge and small throttle opening positions. This valve, therefore,controls the pressure of the fluid fed to the selector valve for use inactuating the two clutches |0 and The pressure control valve is providedwith a, cylindrical body portion 224 (see Fig. 3) on the central axis ofwhich is slidabiy mounted a valve stem 226. This valve stem has slidabiymounted thereon two valves 221 and 228 which are seated in the oppositeends of the central opening through the body portion 224. Toward theright hand end of the valve cylinder there is provided a cylindricallyshaped abutment member 229 which has a recess 23| in its inner end, theabutment portion 229 extending outwardly from the cylinder opening.'I'he valve stem 226 has an extension which abuts against the base ofthe inner recess 23| and there is provided a spring 232, one end ofwhich reacts against the inner face of the recess 23| and the oppositeend against the valve 228. In the opposite end of the valve a spring 233is so mounted as to react between a plug 236 at the end of stem 226 andthe valve 221, thereby tending to hold said valve 221 upon its seat.Also at this end of the pressure control valve and mounted in thepressure control valve cylinder 223, there is a spring 234 which reactsbetween the plug 236 and a plug 236a which closes the end of thecylinder 223.

In operation, oil under pressure from the conduit 222 enters thepressure control valve through conduit 231. By a system of levers, whichwill later be more fully described, the throttle control position isreflected by the movement of a lever 238, the end of which lever abutsagainst the projecting cylindrically shaped abutment member 220. Asshown in Fig. 3, small throttle openings are indicated when the end oflever 238 is near the maximum position to the right, and increased Aspressure is built up in the cylinder 201 by the throttle openings areindicated by movement of compressing the spring 234 and releasing spring233 to a greater extent and causingvalve 221 to oifer less resistance tothe oil from conduit 231 and therefore releasing a larger pressure.

The outlet valve 223 is held closed by spring 232 and when the pressureinside the pressure control valve exceeds that necessary to lift valve228 olf its seat the pressure will be reduced by outlet of fluid to thesump through valve 228. The spring pressure holding valve 22|!` on itsseat is increased with larger throttle openings by the movement ofabutment 229 to the left. With increase in throttle opening the movementof the valve members toward the left reduces the compression on inletvalve spring 233 and increases the compression on outlet valve spring232, thereby increasing the pressure of the fluid allowed to flowthrough the pressure control valve rto the selector valve as thethrottle openings increase.

(d) Selector valve and connections to actuating units The function ofthe selector valve is to direct the fluid under pressure to properconduits to automatically operate the clutches and the synchronizingunit. A cylindrical opening for movement of the valve is provided by asleeve member 259 which is mounted in a substantially cylindricaldrilled opening in the housing. This sleeve member, provides a pluralityof inlet and outlet openings leading to and from the central cylindricalopening in which a selector valve cylinder 25| .is mounted for slidingmovement. The cylindrical valve 25| has a central opening 252 extendinglongitudinally through its center and has provided on its surfacesuitable grooves and drilled openings, the grooves being for the purposeof connecting certain inlet and outlet passages brought in alignmenttherewith, and the drilled openings being for the purpose of releasingpressure from such outlets which it is not desired to hold underpressure, it being understood that the central opening 252 of theselector valve is connected with the sump. There are two main pressureVconduits leading to the sleeve member 25|) and connecting with theinlet openings thereof, 1'. e., conduit 253 leading from the pressurecontrol valve and conduit 256, which is an extension of conduit 22|, andbrings the pressure directly from the accumulator cylinder 201. It is tobe remembered that the inlet openings in the selector valve sleeve 256(Fig. 4) are drilled through the sides of the sleeve member 256substantially in a horizontal plane through the axis of said sleeve. Asshown in Fig. 4, the conduct 253 leads to an annular groove 253a aroundthe sleeve member 25|), which groove has connecting slots 254 cutlongitudinally of the sleeve, one of which slots being provided at eachside of the sleeve member. From the slots 25| there are drilled openings254a, 25417 and 254e which are spaced as shown in Fig. 4 and extend intothe center of the selector valve.

A similar construction is employed to effect inlets into the selectorvalve from the conduit 256,

as shown at the right hand end of the sleeve 250 in Fig. 4, anannulargroove 256e being provided around the selector valve sleeve 250,said annular groove connecting with grooves 251 on each side of thesleeve member. From the grooves 251 drilled openings 251a and 251bspaced as shown in'Fig. 4 are provided. There have now been describedtwo sources ofpressure coming to the selector valve, each with aseparate system of spaced'inlet openings, any one of which will supplyuid under pressure into thecentral bore of the selector valve cylinderif not closed by the surface of the selector valve.

A system of four outlet conduits, all of which take their pressure fromthe selector valve, is provided to direct the pressure to the twoclutches and to the synchronizer operating unit. These conduits areshown in Figs. 3 and 4 as conduits 258 and 259 for clutch actuation, andconduits 213 and 214 for actuating the synchronizer unit. Each of thesefour conduitsl receives its pressure from conduits leading from the topand bottom of the selector valve sleeve member 250 by pairs of conduitsshown in Fig. 5 as 219 and 280, with connecting drilled openings 219aand 28Da. By inspection of Fig. 3 it is noted that the conduits 258,259, 213, 21.4 are spaced along the selector valve cylinder, the clutchoperating conduits 258 and 259 being located toward the left end, asshown in Fig. 3, and the synchronizing conduits 213 and 214 beingadjacent the right hand end of the selector valve unit.

For the purpose of description of the selector valve unit, it is herestated that conduit 258 carries pressure to actuate the clutch il fordirect drive. The conduit 259 carries fluid under pressure to actuatethe clutch l for eiecting low and over-drive gear ratios, while theconduit 213 carries fluid undenpressure to the left hand end of thesynchronizer cylinder, shown in Fig. 4, for the purpose of moving thesynchronizer voperating shaft 363 from left to right and the conduit 218carries fluid under pressure to the opposite or right hand end of thesynchronizer cylinder to move the synchronizer in the oppositedirection.

The connecting conduits which feed pressure to cylinder 32 (Fig.v1) toactuate the direct drive clutch from conduit 258 are 26| (Fig. 3), 263(Fig. 4), 266 (Figs. 1 and 4) and 261 (Fig. 1). The conduits whichconnect with 259 to feed pressure to cylinder 3| (Fig. 1) to actuate thelow and overdrive clutch I6 are 262 (Fig. 3), 268 (Fig. 4), 269 (Figs. 1and 4) and 21| (Fig. 1). For operating the synchronizer cylinder conduit218 (Fig. 3) extends from conduit 214 and into the right hand end of thesynchronizer cylinder through conduit 211 (Fig. 4a). Similarly, conduit213 for feeding pressure to the opposite end of the 'synchronizer pistonhas connecting conduit 215 (Fig. 3) which leads into conduit 216 (Fig.4a).

The selector valve is shown in Figs, 3 and 4 in position to effect lowspeed drive of the transmission. A groove 29| extending around the outerperiphery of the selector valve 25| connects the inlet conduit 25411(Fig. 4) with the outlet conduit 259 (Fig. 3) thereby feeding pressureto clutch lll. It is noted that the drilled inlet opening 25412 is arestricted opening and that therefore the fluid under pressure is fed insuch manner as to effect a slow engagement of the clutch I0. Referringto Fig. 3 it is noted that a drilled opening 292 is provided in the topand bottom of the selector valve cylinder which aligns itself with theconduit 258 leading to the direct drive clutch Il, and because of thisalignment of the drilled opening 292 with the conduit 258 any pressurewhich may exist therein is released into the central opening 252 of theselector valve which is connectedwith the sump through suitable drilledopenings.

As the speed of the car increases the selector valve is moved from rightto left, as shown in Figs. 3 and 4, by the movement of the differentiallever 281, and during the time which the low speed clutch has beenengaged, as above described, a groove 294 of the selector valve has beenaligned to feed pressure to the conduit 213 (Fig. 3), receiving suchfluid under pressure from inlet opening 251b (Fig. 4). Alsoa drilledopening 299 (Fig.

Y 3) has been aligned with conduit 214 to release pressure from saidconduit and from the right hand end of the synchronizer operatingcylinder. 'I'he result of this connection of the conduits 213 and 214has moved the synchronizer unit to connect the gears 24 and 25 with theshaft I4 (Fig. 1), such connection of gearing being necessary to effecta low speed drive, as was previously described in connection with thegeneral gear arrangement.

Continuing with the description of the effect of further increase in thespeed of the car and the movement of the selector valve toward the left,

as viewed in Figs. 3 and 4, a drilled opening 299 (Fig. 3) in theselector valve comes into alignment with the conduit 259 and releasesthe pressure therein through the restricted opening of said conduit 299,thereby producing a slow release of the low speed clutch. 'I'he samemovement of the selector valve places the groove 29| m alignment withthe conduit 258 for actuating the direct drive clutch, the pressurecoming to the groove 29| from the unrestricted opening 254ev (Fig. 4).The result of this movement has been to release the low speed clutch I9and to actuate the direct drive clutch II, a reversal of the conditionpreviously existing. Subsequent movement of the selector valve towardthe left after the above reversal of the clutches has been effectedplaces a groove 295 in alignment with conduit 218 (Fig. 3), thus feedingpressure from the drilled opening 251b (Fig. 4) and placing drilledopening 296 (Fig. 3) in alignment to release pressure from conduit 213.The result of this movement of the selector valve is to feed pressure tothe right hand end of the synchronizer operating cylinder 99| (Fig. 4)and release pressure from the left hand end of the cylinder, therebyproducing movement of the synchronizer from right to left, as viewed inFig. 4. It is noted that this movement is taking place during the timethe direct drive clutch is in operation. This pressure ilow continuesuntil the synchronizer has been moved to its maximum left position (Fig.1), thereby connecting the gear I1 with the shaft I4. No change in driveresults with this movement since the clutch I9 is at this timedisengaged. However, on furtherV increase in car speed and furthermovement of the selector valve from right to left, as shown in Fig. 3,a. longer annular groove 292 is brought into alignment with the conduit259 (Fig. 3), thereby again actuating the clutch I9 to which the conduit259 feeds pressure. Referring to Fig. 4, the pressure comes into thegroove 293 when said groove bridges the two inlet drilled openings 254aand 254b, thereby effecting an unrestricted flow of fluid to actuate theclutch instead of the restricted now afforded by 254D alone on theprevious actuation of the clutch. It is understood that with thesynchronizer in the maximum position toward the left, as abovedescribed, the gear ratio ef fected is an over-drive, as previouslydiscussed with reference to the general gear arrangement.

(e) synchronizer, control cylinder and control Parts As previouslymentioned, the synchronizer is actuated for the purpose of changing thegear connection of one of the clutches while the other is engaged. Inits general construction the synchronizer unit is similar to units usedin other manually operated transmissions wherein the driver of the carchanges the gear connection while the clutch is thrown out. Theessential parts of such a unit are shown in Fig. 1 at I 9 and comprise asliding hub member which carries conical shaped surfaces which onsliding movement of the member will frictionally engage other conicalsurfaces on adjacent rotating parts, thus gradually bringing the tworotating parts up to the same speed oi' rotation, and after this isaccomplished the shafts are permanently connected by movement of acollar which is provided in its inner circumference with toothedprojections which are designed to fit with projections on the hub andonthe adjacent rotating member thereby completing a positive connection.As shown in Fig. 1, the unit designed for use with the transmission hasseveral novel features. A hub 49I mounted free to slide on shaft I4 andsecured to rotate therewith has conical surfaces 492 and 493 providedadjacent its ends and has a sliding collar 494 which is normally heldfrom axial movement relative to the hub 49I by a plurality of springurged balls 495 which are pushed outwardly from the periphery of the hub49| into a groove 496 in the inner surface of the collar. When thesynchronizer collar is moved to the right or left, as shown in Fig. l,by the action of the previously mentioned synchronizer fork, the conicalsurfaces 492 or 492 will contact adjacent surfaces on the gear membersI9 or the gear I1 and by this frictional contact will bring thesemembers up to the rotative speed of the synchronizer hub and shaft I4before the connection is nally completed by the movement of the collar494, which movement occurs when the force to shift the collar issufficient to break the holding force of the spring connection effectedby the balls 495. When this connection is broken the two rotatingmembers are connected positively together by the intermeshing of theinternal teeth on the inside of the collar 494 with teeth on the hub ofgear I1 or on the hub of gear Il.

A greatly improved means of effecting frictional contact of the conicalsurfaces is provided, as shown in Fig. 1, by the use of a floatingmember 491 having two inner conical surfaces so that when the conicalsurface 492 of the hub 49| con tacts one of these surfaces the memberwill slide along with the hub member and contact another surface on anadjacent floating member 498. In this manner a plurality of surfaces isprovided and results in a greater frictional torque, thereby bringingmembers Il and 49I to the same rotative speed in much less time thanwould be possible with a single frictional surface, provided the samepressure be applied in each case; or in the same time with less force.In case the same force be used to bring about synchronization in thesame length of time. this construction which employs a plurality ofsuccessively engaged conical surfaces allows the use oi a relativelylarge contacting angle and provides the same synchronizing power as witha single surface and asoasss smaller angle. The larger contacting angleis of advantage because cones of greater angle have less tendency tostick together after the pressure is removed. thereby leaving themembers I3 and 40| free to turn slightly with respect to each other,after the holding force of the balls 403 has been broken, to permit theteeth on lcollar its travel followed by a pause during the portion ofthe travel in which the synchronizing cones are being held in contact,followed by a fast movement for quickly effecting a positive connectionby engagement of the projecting teeth or jaws on the inner surface ofthe collar with the adjacent gear unit.

For the purpose of effecting theabove outlined result a fluid pressureoperated synchronizer cylinder 30|, see Fig. 4, is provided, theprimary.

partsbeing the :fluid pressure operated piston 302 with slidably mountedshaft 303 and shifter fork 304. The shifter fork 304 is connected withthe synchronizer proper by the conventional circumferential recess 306.The connections of the fluid pressure system to this unit havepreviously been indicated up to the points 21S and 211 in Fig. 4a. Inoperation when, for example, the position of the selector valve is suchas to require a movement of the synchronizer to the right to connect thelower gear ratio unit l0, the selector valve will allow fluid underpressure to enter through the opening 216 and pass out through theopening 211. A check valve is used at both of these openings whichessentially comprises a star-shaped plate with`a small orifice in itscenter mounted in both of the openings 216 and 211. When the flow offluid under pressure is into the opening 218, for instance, thestar-shaped plate 301 is caused to move upwardly off the 'opening 213and allow unrestricted flow therethrough and the movement of the pistonforces fluid out of the opening 211 and causes the starshaped plate 301in that opening to rest against the fiat surface and restrict the flowtherethrough. The result accomplished is an unrestricted inflow at oneend of the cylinder and a restricted outflow at the other. It is notedthat there are two other outlet ports 308 and 309 a distance from theends of the synchronizer'cylinder. (See Fig. 4a.) Considering themovement of the piston to the right, the port 309 during the firstportion of the travel being uncovered by the piston allows substantiallyunrestricted outward flow, and, therefore, fast movement of the pistonduring the first part of the travel. However, as the piston covers theport 309 the piston moves more slowly as the flow is then restricted bythe aforementionedstar-shaped plate 301a.

A pause in the motion of the synchronizer during cone contact isassuredby the manner of mounting the piston 302 upon the shaft 303. As shown inFig. 4 the end of the shaft 303 projects into the recessed inner portionof the piston 302 and is yieldably secured to said piston by two springs3| i and 3|2, these springs being on opposite sides of Van abutment 3|3on the shaft 302. Suitable details to assure the reaction of the springsagainst this abutment are provided, namely, two rings 3I4 and 3|3 and alocating ring 3|3 in the piston. The spring connection -member duringthe approach or idle portion of v -above described permits the shifterfork and synchronizer to stop when the cones make contact. The piston302, however, continues to move slowly during this period, its rate ofmotion being controlled by the star-shaped orifice 301 or 301e. Themovement of piston 302 against spring 3|| g or 3|2 builds up a pressurewhich serves to press the conical surfaces of the synchronizer togetherfor satisfactory frictional engagement to perform the function ofbringing the new gear train to the same speed of rotation as member 40|.The strength of the springs 3H and 3I2 and the size of the hole in thestar-shaped orifice 301 or 301e are such that this pause continues asufficient time so that synchronization is completed before enoughpressure is built up on spring 3|| or 3i2 to cause the shifter fork andshaft to disconnect the collar of the synchronizer. A final relativelyfaster movement of the synchronizer collar to eect final connection `oithe unit will result from the ensuing release of spring 3|I or 3|2. Thislast movement may be better understood by reference to Fig. 1, whereinthe sliding collar of the synchronizer is shown. Considering thesynchronizer moving to the left, it is apparent that the cones arebrought into contact by movement of the entire synchronizer. During thetime when the spring -3|| is being compressed and until suillcientpressure is built up by the spring 3H, the collar 404 and hub 40| of thesynchronizer unit will not move longitudinally. After suflicientpressure is built up to break collar 404 away from the ball retainers,-a fast movement will eect the final connection of the gear Il to theshaft i4 by meshing of the internal teeth of the synchronizer'I collar404 with the teeth on the gear member I1.

The synchronizer cylinder 302 as shown in Fig. 4a is constructed with anannular groove 302e and a drain 30211 is provided in the wall of thesynchronizer cylinder so that any leakage past the piston is drainedback to the sump. In this way leakage of pressure past the piston isprevented from building up a back pressure on the outlet side therebyassuring that full inlet pressure will Yalways be available to move thesynchronizer piston. This construction was previously mentioned inconnection with the diagrammatic showing in Fig. 2.

(f) synchronizer and selector valve interlock Still referring to Fig. 4,it is to be noted that there are two recesses 3|1 and 3|8 so positionedthat when, for example, the movement of the synchronizer shifter fork304 to the right is complete the recess 3|1 will come into alignmentwith a pin 310. This pin is mounted to have a beveled projecting endsuitable for contacting a beveled ring 32| on the selector valve 25|.During the time that the shifting has been taking place the end of thepin 3|! has been in contact with the ring 32| andv has prevented themovement of the selector valve, but on the completion of the shift thepin 3I9 drops into the recess 3|1 on coming into alignment therewith andthe selector valve is released. In other words, the mechanism justdescribed assures that the selector valve cannot move to apply clutch i0until the synchronizer shift is completed, and collar 404 is in positionto transmit the power applied through clutch |0. The action is similarwhen the synchronizer completes its movement to the left, pin 320 beingbrought into alignment with recess 3I0, thereby releasing the selectorvalve for movement toward the left with increase in speed.

(g) Governor operated by vehicle speed Referring to Flg. 1, there isshown a. governor mounted on the end of the shaft I4 at the rear of thetransmission housing. 'I'he housing 350 for this governor unit is shownas bolted to the end of the main transmission housing and this housingalso includes a bearing 35| and a speedometer drive gear 352 so mountedas to make possible the assembly of a conventional fitting 353 forconnection to the propeller shaft of the vehicle. The governor itself ismade up of a member 354 which is secured to rotate with the shaft I4. Aplurality of bosses 356 project radially out from the fitting 354 andhave pinned thereto counterweight arms 351. Similarly shapedcounterweight arms 358 are secured to a sliding collar 359 mounted toslide upon the shaft I4. Weights 35I are mounted on the pins whichconnect the two counterweight arms 351 and 358 so that when the shaft I4rotates carrying with it the member 354, the counterweights and arms andthe collar 359, the speed of rotation causes the weights 36| to bethrown outward .by centrifugal force. A spring 352 is mounted betweenthe member 354 and the collar 359 and the centrifugal action of theWeights 36| is therefore resisted by the spring 362 and therefore thelocation of the collar 359 on the shaft I4 is indicative of the speed ofrotation of the shaft I4. It is also contemplated that a governor mightbe used employing a plurality of springs of differential effect designedto cause the valve mechanism to shift at suitable vehicle speeds, asdisclosed in my co-pending application, Serial No. 715,065. In thedesign here shown the collar 359 has an annular recess 353 in which asuitable projection on a lever 364 is adapted to fit in such manner thatwhen the collar 359 slides on the shaft I4 the lever 354 will be carriedtherewith. (See Fig. 1*.) It is to be noted that an increase in speed ofthe shaft I4 causes the top end of the lever 354 to swing toward 'theleft as shown in Fig. 1.

(h) Controls from governor and throttle to dilerential lever Aspreviously mentioned, the selector valve which directs the flow of fluidunder pressure to the several mechanisms is controlled by the combinedaction of throttle control position and vehicle speed. A differentiallever 281 shown in Fig. 3 is pivotally mounted at its center on theprojecting end of the selector valve 25I. One end 288 of this lever 281(the lower end as viewed in Fig. 3) is actuated by the vehicle speedgovernor and the opposite end 289 is actuated by a member which moveswith the throttle'control, as will now be described.

To transfer the governor movement to the end of the differential lever'281 the mechanism shown in Figs. 1, 7 and 8 is provided. As shown inFig. 7, the end of the lever 364 is connected by a rod 356 to a lever361 projecting downwardly from a shaft 358 (see Figs. 1 and 8) whichextends transversely across the top of the transmission. It will beapparent from inspection of Figs. 1, 7 and 8 and on consideration of thedirection of the movement of the governor that clockwise rotation ofshaft 358 as viewed in Fig. 1 would indicate increase in vehicle speedas reflected by the main shaft I4 of the transmission. Also referring toFig. 6 wherein the shaft 353 is shown with a depending lever 369 securedthereto, it is noted that the end of the lever 369 is secured to the endof the differential lever 281, thereby completing the connection fromthe governor to the end of the differential lever, as shown at 288 inFigs. 3 and 6.

By appropriate linkages the engine throttle control is connected torotate the shaft 31| shown in Fig. 3 in such a manner that clockwiserotation of the shaft 31I as viewed in Fig. 3 is lndicative of increasein throttle opening. The

, shaft 31| is also shown in Fig. 6 and is secured to a lever 238 whichis connected to the top end of the differential lever 281 by link 312.The lower extension of lever 238 also acts to apply the pressure controlvalve by contact with the projecting end 229. By the connection effectedby the upper portion of lever 238 the throttle control is connected tothe opposite end 289 of the differential lever 281 from that used toconnect the governor control and makes possible the positioning of theselector valve by the combined action of throttle control position andvehicle speed. A spring 313 is mounted to hold the top end of thedifferential lever 281 normally toward the left (Fig. 3) and the openingaction of the throttle rod is to move the lever in the oppositedirection. There is also provided a spring 314 which serves to controlthe movement of the selector valve by contact with suitable projectionson the projecting surface of the valve, thereby to define the stepsinthe movement thereof, as shown in the diagrammatic view Fig. 2.

In Figs. 3 and 6 there is shown a member 288a which is L shaped and ispivoted on the end of the shaft 31| and free to tilt about this pivot.The end of the member sets against the end of the pressure control valve229, as shown in Fig. 3, and the projecting portion is so shaped thatwhen the governor control at 288 is so positioned as to indicate arelatively high vehicle speed the end of the member 288 will hold themember 288e against the end of the pressure control valve and prevent itfrom entirely releasing the pressure, which would result whenever thethrottle was released, regardless of the speed, if this stop were notprovided. The throttle lever 238 has a projecting end which controls themovement of the pressure control valve and when the governor controlmember 288 is in a relatively low speed position, as shown in Fig. 3,small throttle openings will allow the pressure control valve to extenda maximum distance to the right, which condition will release allpressure and throw out any clutch which may be engaged, therebyproducing a neutral (or free wheeling) condition, and permit the car tobe stopped without stalling the engine. 'Ihe above described mechanismallows such a condition to occur only at relatively low car speeds andreleased throttle, whereas at high car speeds the free wheeling of thecar is prevented by the action of the member 288e which is held againstthe end of the pressure control valve.

(i) Reverse interlock In order that it will not be possible for theautomatic control of the transmission to throw the gearing into highgear when the manual shifting mechanism has been used to place the gearsin position for a reverse drive, the mechanism shown in Figs. 8 and 9has been provided. The shifter fork 28 shown in Fig. 8 is for thepurpose of moving the reverse idler along the shaft 2| and as shown inFig. 9 a two armed lever 4l! is mounted with one of its arms 45|positioned to ride upon the top of the shifter fork arm 28 when saidfork is in such longitudinal position as to effect reverse drive. Such apositioning of the lever as is shown in Fig. 9, produced when it isriding on top of the fork 28, positions the end 452 of the leverupwardly toward a projecting arm 453 secured to be rotated with theshaft 368 which it will be remembered is actuated by the vehicle speedgovernor and is connected through several leverages to actuate theselector valve. The result of the aforementioned positioning of the end452 of the lever 450 is to place it in position to act as a stop so thatthe shaft l, and therefore the selector valve, cannot be actuated toeilect high lgear. When the shifter fork is actuated to place thereverse idler out of operation by longitudinal movement of the fork 28it is apparent that the lever 45| will drop by gravity out of the wayand be positioned against a stop pin 454 lshown in Fig. 9, and in suchposition will allow the shaft Il! and its connected partsl to operatewithout interference.

(i) Clutch operating mechanism and support in transmission housing Inthe design of the present type of transmission which includes the use oftwo so-called dry plate clutches mounted in a flywheel housing I2, shownin Fig. 1, combined with a fluid pressure mechanism to operate the dryplate clutches mounted adjacent thereto, it was a definite requirementthat the use of an excep tionally heavy and cumbersome rotating weightsuspended at the end of the flywheel housing be avoided. A heavyoverhung weight, if no support were provided on the cuter end, would bevery objectionable as it would throw heavy loads on the end of thecrankshaft and an the flywheel and clutch housing. There is anotherimportant problem in this connection in that it is very important thatnone of the fluid which is used to actuate the huid pressure mechanismcan be allowed to be thrown from the rotating unit toward the clutches.Both of these problems have been considered and solved by' the novelconstruction which is shown in Fig. l. The entire overhanging portion ofthe fluid pressure actuating unit is supported in the large bearing 50Dprovided in the collector ring casing 460 which is secured to thetransmission housing and serves both as a means to carry the collectorring conduits 286 and 269 as well asv to provide a bearing for therotating unit. It has been previously mentioned that all of the pistonsfor actuating the clutches rotate with the flywheel and such aconstruction is shown in Fig. 1. The piston housing 30 projects into theflywheel portion of the transmission housing and rotates with theiiywheel but the entire unit is provided with a cup-shaped cover 46|with a flange edge 462 which extends back into the next compartmentrearward of the flywheel casing. When the unit rotates this cup-shapedmember collects such oil as may leak past the pistons, the centrifugalforce causing this oil to fiow back on the cupshaped member to theflange 452 from which it is thrown on the adjacent wail of thestationary casing to flow into a sump groove 463, which groove isprovided with a drain to allow the oil to now back into the oil sump.This construction makes possible the use of the dry plate clutchactuated by a fluid pressure unit which rotates with the clutches butdoes not have the very objectionable feature of uid conduits adjacent toit with the possibility of leakage into the clutches. As previouslynoted,

the housing 30 is secured by set screw 30a to iiywheel I2 and thereforeendwise reaction from the pistons is transmitted to the ywheel and isnot imposed on the bearings in the transmission or engine. The housing3D is mounted with a limited lateral freedom of movement so that axialmisalignment between the rotating flywheel clutch housing and thetransmission unit will not seriously interfere with the cooperativeoperation of the housing 3l and the parts with which it rotates. Thisfreedom of movement is made possible by a loose mountingy of thecollector ring casing 440 in the transmission case at 485 and also by aloose mounting of the projecting end of the housing 30 at 488 where itconnects with the rotating flywheel I2. The right hand end of thehousing 30 rotates in the collector ring casing Il so that the saidcollector ring casing 460 and the housing 30 form a unit which, togetherwith the sleeve I5, has a limited freedom of tilting movement because ofthe loose mounting, the end of the sleeve I5 being secured to the clutchplate and free to move on release of the clutch. By the above describedmounting it has been found that such misalignment between the iiywheeland the ad- `jacent parts is adequately compensated so that asatisfactory mounting of the several rotating parts is accomplishedwithout objectionable binding due to misalignment.

(k) Details of clutch construction to adapt for automatic operation Itis very advantageous in connection with a clutch which is to be actuatedby iluid pressure mechanism that there be some kind of a cushioningmeans provided giving a delayed action so that `when the fluid pressureis applied by whatever means is used to push the plates of the clutchtogether there will be a time interval after which the clutch will makepositive engagement. It has been found after a considerable period ofexperimental work that the use of a clutch facing with a resilientmounting such as shown in Figs. 11 and 12 produces very desirableresults. As shown in the two figures, one clutch facing 410 is securedto the clutch plate by rivets without resilient mounting, while thefacing on the opposite side of the plate 412 has a plurality of springclips 413 bent into the shape as shown and riveted at the center to theclutch facing and at one end to the plate. The result of such aconstruction is to resiliently mount the clutch facing relative to theplate so that when the clutch is engaged in the usual manner it willtake up slowly because of the use of the resilient mounting.

Although I have described my invention as applied to a specific type ofunit found practical in actual operation, I do not desire to limitmyself to the exact details of the construction shown and describedherein but rather to the scope of the following claims.

I claim:

1. In a variable speed power transmission system including a clutch anda speed ratio changingl mechanism, fluid pressure operated mechanism foractuating the clutch comprising a fluid pressure operated mechanismhousing member mounted for rotation with the clutch, fastening meanssecuring one end of said member with limited freedom of movement fromconcentric alignment with said clutch, and a. bearing supporting theopposite end of-sai'd member adjacent said speed ratio changingmechanism.

2. In a variable speed power transmission system including a clutch anda speed ratio changing mechanism, fluid pressure operated mechanism foractuating the clutch comprising a fluid pressure operated mechanismhousing member mounted for rotation with the clutchfastening meanssecuring one end of said member adjacent said clutch, a bearingsupporting the opposite end of said member adjacent said speed ratiochanging mechanism, said fastening means and said bearing being mountedto allow limited freedom of movement of said member whereby said memberwill rotate freely regardless of small variations in relative alignment,with said clutch and said speed ratio changing mechanism.

3. In an automotive transmission mounted rearward of a rotatingflywheel, a. clutch mounted in said flywheel having an element thereofrotating therewith, fluid pressure actuated mechanism for operating saidclutch, also mounted for rotation with said flywheel, a housing forsupporting said fluid pressure mechanism, an extension of said housingcarrying conduits for supplying fluid pressure to said mechanism,supporting means for said housing forming a bearing around saidextension and having conduits aligning with conduits in said extensionmember thereby serving as a collector ring unit for feeding fluid underpressure to said rotating fluid pressure actuated mechanism.

4. In a power transmission system, a clutch, fluid pressure operatedmechanism for actuating said clutch comprising a fluid pressure operatedmechanism housing member attached to the clutch for rotation therewith,a source of fluid pressure, and means secured adjacent said memberincluding a defiector whereby the rotation of said member serves tothrow leakage fluid'from said actuating means onto said def-lector forreturn to said scurce of fluid pressure.

5. In a variable speed power transmission system, a plurality ofclutches mounted for rotation with a common supporting member, a set oflevers for actuating each of said clutches, and fluid pressure actuatedmeans for operating said levers mounted for rotation with said clutchesand said supporting member.

6. In a transmission having a driving shaft and a driven shaft, meansfor effecting various speed ratios between said shafts including aclutch, a fluid pressure pump, fluid pressure means for actuating saidclutch, valve means interposed between said pump and fluid pressuremeans for regulating the rate of flow of fluid to said fluid pressuremeans and thereby the rate of engagement of said clutch, and means forretarding disengagement of said clutch to prevent jerky operationthereof when changing from one speed ratio to another.

7. In a transmission having a plurality of clutches actuated by fluidunder pressure, characterized by a selector valve for selectivelydirecting fluid under pressure to and from the clutches, said valvehaving restricted outlet ports whereby gradual release of clutches iseffected.

8. In a transmission, a plurality of clutches, a source of fluidpressure, a sump, fluid pressure mechanism for operating the clutches,conduits leading to said clutches, a selector valve having inlet andoutlet ports for selectively connecting said source of fluid pressure orsaid sump with said clutches, and members forming a restriction in theoutlet ports of said selector valve whereby gradual release of clutchesis effected.

9. In a transmission system for automobiles including a friction clutch,means for actuating said clutch including fluid pressure operatedmechanism, an element responsive to variations in atmospherictemperature conditions, and means connecting said element with saidfluid pressure mechanism whereby the rate of application of said clutchis varied in accordance with changes in temperature.

10. In an automotive transmission providing a range of gear ratio, amovable member for effecting change in gear ratio, automatic fluidpressure actuated mechanism for causing movement of said member atvaried rates at different portions of its travel comprising a housinghaving a cylindrical opening therein, a piston connected to operate saidmember and mounted for movement in said cylindrical opening, fluidpressure conduits having ports of various sizes opening into saidcylindrical opening in such position a's to produce movement of saidpiston and in such relative position that restricted ports are leftuncovered by said piston during one portion of its travel and largerports during other portion-s of its travel thereby providing variationin rate of movement of said piston and said operating member.

l1. In an automotive transmission providing a range of gear ratios, amovable member for effecting change in gear ratio, automatic fluidpressure actuated mechanism for causing movement of said membercomprising a housing having a cylindrical opening therein, a pistonmounted for movement in said cylindrical opening, fluid pressureconduits for feeding pressure into said cylindrical opening on one sideof said piston and out of said cylindrical opening on the opposite sideof said piston thereby to move said piston, and a resilient connectionbetween said member and said piston whereby said piston is allowed tomove independently of said member by action of fluid pressure on saidpiston and produce a pause in its movement followed by a relatively fastmovement of said member when said resilient con nection has beencompressed by said piston movement.

12. In an automotive transmission providing a range of gear ratio, amovable member for effecting change in gear ratio, automatic fluidpressure -actuated mechanism for causing movement of said membercomprising a housing having a cylindrical opening therein, a pistonconnected to operate said member and mounted for movement in saidcylindrical opening, a pair of conduits for feeding fluid to and fromsaid cylindrical opening, one conduit leading to each end of saidcylindrical opening on opposite sides of said piston, check valvemembers mounted in said conduits in such position that restriction offlow is afforded when movement of fluid is away from said cylindricalopening and unrestricted flow is afforded when flow is in oppositedirection thereby to place full conduit pressure on the side of saidpiston to which pressure is admitted and to provide restriction of flowto control movement of said piston by the operation of said check valvein the conduit releasing fluid from the opposite side of said piston.

13. In an automotive transmission, a friction clutch, fluid pressureoperated mechanism for actuating said clutch, means to vary the pressureapplied to said fluid pressure mechanism during the time required foractuation of said clutch comprising mechanism to allow pressure to buildup quickly during the initial period required for actuation of saidclutch and further mechanism to apply pressure more slowly during thelatter portion of the period required for actuation of said clutch.

14. In a fluid pressure mechanism for operating a clutch, means in saidfluid pressure mechanism for assuring a rapid build-up of pressureduring the initial period of application oi pressure to actuate saidclutch followed by a slow build-up of pressure during the later periodof said pressure application, said means comprising a branched conduitfor feeding pressure to said clutch, an unrestricted opening in one ofsaid branches and a restricted opening in the other of said branches, acheck valve operable to close said unrestricted opening at apredetermined pressure under the maximum pressure available to operatesaid clutch, whereby said unrestricted opening is closed by operation ofsaid check valve at a pressure below said maximum and a pressure iiow isrequired to pass through said restricted opening in the opposite branchthereby requiring a slow build-up of pressure during the remainder ofthe time required to attain the maximum pressure available in saidsystem.

15. In a power transmitting system for automobiles, an engine, athrottle for controlling the engine, a clutch, iluid pressure means foractuating said clutch comprising means for graduating the actuatingpressure in accordance with throttle position, and thermostatic meansfor varying the relation between the clutch actuating pressure andthrottle position.

16. In a fluid pressure operated automatic transmission mechanism havinga pressure control valve for varying the pressure used to actuate saidtransmission in proportion to the extent of the throttle opening, amember indicative of the extent of throttle opening connecting saidthrottle with said pressure control valve, and a thermostatic elementassociated with said connecting member to vary the effect of themovement of said connecting member in proportion to variation intemperature conditions.

17. In an automobile having a throttle for controlling engine output, anaccelerator for operating said throttle, a iiuid pressure actuatedclutch, connections between said clutch and said accelerator whereby theactuating pressure for said clutch is varied in accordance with saidaccelerator position, and thermostatic means to maintain a deniterelation between engine output and clutch application for any positionof said accelerator regardless of changes in temperature.

18. In a fluid pressure operated transmission for an automotive vehicleusing throttle contro1 position as one of its control elements, a memberindicative of position of said throttle control, a pressure controlvalve operated by said throttle control to provide iluid under higherpressure at greater throttle openings and lower pressure at smallerthrottle openings, comprising a valve stem actuated by said throttlecontrol position indicative member, a valve controlling fluid, a springmounted to urge said valve toward closed position and mechanism operatedby said stem to vary the compression of said spring thereby to allowsaid valve to open at varying pressure thereby to change the pressure inthe system in proportion to a movement of said valve stem and saidthrottle'control position indicative member.

19. In a mechanism for automatic operation of a synchronizer of the typeoperated by sliding movement of a collar, the tlrst movement oi whichbrings two surfaces in frictional contact for bringing rotating parts tothe same rotative speed and by the use of greater pressure moves saidcollar to effect a positive engagement of the rotating parts, operatingmeans for moving said collar comprising a iluid pressure operated pistonmounted in a housing having a cylindrical openingproviding for inlet ofiluld pressure on one side of said piston and outlet of iiuid pressureon the opposite side of said piston for producing movement thereof, amember connecting said piston with said collar and a resilientconnection between said member and said piston whereby said piston isallowed to move independently of said member by action of uid pressureon said piston followed by a relatively fast movement of said memberwhen said resilient connection has been compressed by said pistonmovement thereby to move said collar for completing positive engagementoi* said rotating parts.

20. A transmission for automobiles having a plurality of gear ratiocombinations and a plurality of clutches the successive actuation ofwhich renders said gear ratio combinations successively operable,characterized by automatic mechanism for successive operation of saidclutches including mechanism to regulate the rate of release of saidclutches and further mechanism operable independently of said clutchrelease mechanism for eilecting application of said clutches.

21. In an automatic iluid pressure transmission for an automotivevehicle comprising uid pressure operated clutch means, means forautomatically operating said clutch means to render said transmissionoperative including a speed responsive device and means for actuating itin accordance with variations in vehicle speed a throttle actuatingmeans, control means for said fluid pressure operated clutch means,connections between said throttle actuating means and said control meansfor causing increase in clutch operating pressure in accordance withincreased throttle opening and connections between said speed responsivedevice and said control means to prevent disengagement of said clutchmeans when the vehicle is travelling above a predetermined speedirrespective of the extent of throttle opening and automatically topermit complete release of said clutch means when the speed of saidvehicle drops below said predetermined speed.

22. In an automatic -iluid pressure transmission for an automotivevehicle having an engine and a throttle therefor, comprising fluidpressure operated clutch means, means for automatically operating saidclutch means to render said transmission operative including a speedresponsive device and means for actuating it in accordance withvariations in vehicle speed, control means for said iluid pressureoperated clutch means including a. pressure control valve formaintaining an effective fluid pressure, connections therefrom to saidthrottle to vary said pressure in accordance with variations in throttleopenings, and connections between said speed responsive device and saidcontrol means to prevent disengalgement of said clutch means when thevehicle is travelling above a predetermined speed and 23. In a vehicleequipped with propelling means driven from Aa throttle-controlledengine, the

